Shunt connection



Jan. 9,l 1923.

R. B. TAYLOR.

SHUNT CONNECTION.

FILED Minze. 1922.

Patented Jan. 9, 1923.

UNITED STATES PATENT OFFICE.

ROBERT B. TAYLOR, OF CLEVELAND, OHIO. ASSIGNOR T0 UNION CARBIDE 8c CARBON RESEARCH LABORATORIES, INC.,

A CORPORATION OF NEW YORK.

SHUNT CONNECTION.

Application led March 28, 1922. Serial No. 547,447.

To all lwhom t may concern.'

Be it known that I, ROBERT B. TAYLoR, a citizen oi the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Shunt Connections, ot which the following is a specification.

This invention rela-tes to means for attaching flexible electrical conductors to currentreceiving elements. More particularly, the invent-ion comprises an improved construction adapted to connect shunts or cables to the brushes of dynamo-electric machines.

In accordance with prior practice, shunts may be attached to brushes by drilling an opening` therein of somewhat larger diameter than the shunt, inserting an end of the shunt in the opening, and compacting a conductive material about the shunt to hold it in position. The lateral engagement of the compacted. material with the walls of the opening is alone depended upon to maintain the connection. To secure an adequate engagement of this kind, it is necessary to tamp the material with considerable force, resulting in frequenti breakage,v especially whenrelat-ively soft and frangible brushes are used.

In the preferred embodiment of the present invention, an improved tamped connection is provided by anchoring a metal sleeve in an opening in the brush and compact-- ing the conductive material about the end of the shunt inserted in the sleeve.

The invention will be described in connection with the accompanying drawing, in

' which Referring to Figs. l and 2 of the drawings, numeral l denotes a brush having a bore 2 adjacent one side and extending downwardly, preferably at an angle, from the top of the brush. An angle oit 15o to the perpendicular through the center of the brush is preferred. The bore is widened at its bottom to provide a recess 3, which will in general be elliptical with its longer axis approximately parallel to the wider faces ol the brush. However, recesses of circular or any other suitable conformation may be provided. The recess may be easily formed by using a drill having a short cutting head mounted on a stem of less diameter. Then the proper depth is reached, the drill is shiftedy laterally and rotated to undercut the wall of the bore.

A metal thimble 4, cut away laterally as shown in Fig. 2, is inserted in the bore, and an outturned marginal flange 5 sustains the thimble with its base above the recess 3. A plate 6 ot' metal 0r other suitable material, adapted. to be engaged by pressure-applying means for 'forcing the brush against the commutator, may be provided. The plate (5 perforated. at 7 to permit the passage ot thimble 4 and the outturned flange 5, overlying the plate, retains it in position. The plate may carry a finger piece 8 for lifting the brush,

The thimble 4 is anchored in the brush by embedding its lower end in a molten or plastic material 9 adapted to solidify into avstrong, coherent mass. I prefer to use type metal in this connection. The met-al is melted and poured into the bore 2 in amount sullicient to fill the recess 3 and the lower portion of the bore. On cooling, the metal expands very slightly/f. thus insuring close engagement and good electrical contact with the thimble and the wall of the bore. The solidified metal body is incapable ot. upward displacement, owing to its engagement in the enlargement at the bottom of the bore.

The thimble is securely anchored in or linkedv to the metal body by its cud being ein bedded therein, and yis therefore effectively retained.

Instead of type metal, l may use other alloys. These should in general have a fairly high melting point, to prevent sottening should the brush become hot, and they should not contract much on solidifying. Phenolic condensation products may also be used to anchor the thimble in the brush.

A shunt l0 ot somewhat smaller diameter than the thimble is inserted therein, with .its end adjacent the anchoring` material 9. .er conductive, cementing composition ll is then tamped between tl e shunt and thimble. The composition ll is preferably copper amalgam, and may be of the kind described in Patent No. 1,199,635 granted to ll. B. Eynon, of J une 27, 1916. However, the invention is not limited to any particularconductive cement.

The cementing` composition 1l in plastic condition forced into close contact with the thimble l and the wallet the openingin the brush. The composition hardens into afbloclr having ashouldcr 12 engaging ring` 13 at the head oit the thimble. ln this manner greater security against loosening and displacement et the cementingr composition is obtained than when only the lateral engagement or the cement is effective. A braided conductor or cable will ordinarily be used. The surface irregularities of suoli conductors are entered by the plastic, which upon solidifyingy securely binds the conductor in the desired position.

inthe form ofthe device illustrated in Fig'. 3, the thimbleis replaced by a tubular rivet having one end 1.5 expanded into recess 3. The end ot' a shunt 10 is then inserted in the rivet and aconouctive cementing` material l1 tamped in. The rivet may be cut away las at 16.

Fig; t illustrates means for securing a plate upon the brush when only one cable connection is desired. A recessed bore 2 and thimble 4, ot the type described, are pro vided, and a` rivet 17 is inserted in thc thimble. The rivet has a head 18, overlying flange 5, and anenlarged lower end'l9, which is embedded in typemetal or other suitable cemei'iting material 20. In this manner the rivet is securely linked to the immovable 'ceinenting body inthe bore and retains that end of theplate .6 which is not held by the connection carryingv shuntV l0.

I have illustrated by way ot example a carbon brush carrying two shunts, 10 and 10V', and having a pressureplate 6 andiingrer piece 8 through which torce to press the brush against its coacting` surface, or to remove it from said surface, may be applied. lllhile the structure described herein aii'ords a simple and etliective meansv for securing such torce transmitting members, these members may olf' course be omitted when not required. One or more shunts may be atnaaneao tached, as desired. Thebrush may consist of a metal alloy, metahgraphite composition, or other suitable material. T he invention is particularly applicable, however, to relatively 'trangible carbon brushes, as the thimblc or rivet protects the carbon from much olf the disintegrativc effect` of the tamping pressure. .ln some cases I may use the same material as both thimbleanchoring and shunt-holding means. For example, type metal may be poured about the end ot a shunt properly positioned in the thimblc, or copper amalgam or the lilre may be tamped into the bore and recess so as to hold boththe thimble and shunt in position. Various other modifications ot the specific terms described herein may be made within the scope o't the appended. claims.

claim l.. it conductive block havingfa bore there# in, a conductor,V a-n'ietal sleevein said bore and adapted to r iceivea portion et said Con ductor, and means for securingv the sleeve and conductor in the block.

2. rPhe invention according' to claim l, in which one portion olf the bore is recessed, and the sleeve is provided with means engaging; the recessed portion, whereby movement et the sleeve along` the bore is prevented.

3. A. conductive block havingg` a bore therein, a metal thimble adapted to iit into said bore and toreceive` a conductor, and means overlying' a portion ot thethimble and engaging the bore, whereby displacement of the thinible is prevented.

4. rflieinvention accordingteclaim 3, in which the bore'is recessed adjacent its base, and a cementing material is filled into the bore and recess so-as to embed the lower portion oil the thimble.

5. rlhe invention accordingto claimv il, in which thecementing material is type metal.

6. The invention according to claim et, in which the conductor is securediin the thimble by a conductive, cementing material. com pacted between the thimble and conductor.

7. Theinvention according to claim 6, in which the cementing` material has av shoulder abutting; against a portion ot the thimble.

tl. fr shunt connection for a brush having a here therein., comprising a metal. sleeve in said bore, means ttor securing,-A said sleeve, a shunt having one end inserted in said sleeve, and a cementing material compacted i about-` said shunt and retaining it in the sleeve.

9. A. brush having' an interior cavity, a bore of relatively small diameter connecting,` the cavity with a brush surface, a body et strong` material larger than the bore and located within the cavity, and an anchoring' element extendingthrough the bore and linked with ad body et strong,- material.

10. A brush having a boretherein, a plate upon one surface of said brush and having a perforation overlying said bore, and a cated Within the cavity, and a member adaptmetal sleeve secured in said bore and having ed to transmit a force to the brush, said a flange overlying said plate. member being anchored through said bore l0 ll. A brush having an interior cavity, a to the body of strong material. 5 bore of relatively small diameter connecting In testimony whereof, I ax my signathe cavity with a, brush surface, a body of ture. strong material larger than the bore and lo- ROBERT B. TAYLOR. 

